Structural investigation of (1-methylimidazole)-2,3,7,8,12,13,17,18-octaethylporphinatozinc( II)

[Zn(C36H44N4)(C4H6N2)], [Zn(OEP)-(1-MeIm)], Mr = 680.26, monoclinic, P2(1)/n, Z = 4, F(000) = 1448, a = 14.099 (3), b = 17.762 (2), c = 14.475 (2) A, beta = 95.48 (1) degrees, V = 3608.4 A3, T = 294 +/- 1 K. The calculated and observed densities are 1.25 and 1.26 g cm-3. 5700 observed reflections (measured with Mo K alpha radiation, lambda = 0.71073 A) were used to refine the structure to a final R1 = 0.072 and wR = 0.098. The complex crystallizes isomorphously with [Co(OEP)(1-MeIm)] and similarities and differences in side-chain disorder and core conformations are described. The average Zn-Np bond distance is 2.068 (7) A and the axial Zn-N(Im) distance is 2.106 (4) A. The zinc(II) atom is displaced 0.42 (1) A from the porphyrin mean plane. The 1-methyl-imidazole ligand plane makes a dihedral angle of 10.5 degrees with a Zn-Np vector. This orientation of the 1-methylimidazole ligand corresponds well with that of previously determined imidazole metalloporphyrin structures and further indicates that the preferred orientation of imidazole ligands is essentially insensitive to the dn configuration of the metal ion of the metalloporphyrin.